DroneThermal Analog MAV Cameras, Almost Ready

Hi Everyone,

I'm happy to present the final prototype of DroneThermal micro size analog (PAL/NTSC) thermal camera. 
The project started 3 months ago and we have published some samples on 

our facebook page on 1 March 2015.

After hundreds hours of code work and design changes, the final prototype is ready for production. We signed the agreements with FLIR for Lepton thermal camera cores as well. 

DroneThermal is based on FLIR's low cost 80x60 pixel Lepton camera cores.
Video frame rate and resolution is not much but the price is perfect for civilian small drone hobbyists.
You can pre-order it now, in order to take the advantage of %15 Spring discount.

Composite video signal resolution is higher than Lepton, so we can resize the thermal image and add some extra information into the video output. ( marking hottest and coolest objects etc. )
Unfortunately radiometry(temperature reading)  looks nearly impossible because of high math and affects of air temperature, thickness, pressure, reflection rate of the objects and camera body temperature. 

I'm working on some cool features , so please share your opinions with me for improvements.

Cheers
Melih

Views: 7585

Comment by Nick Fleming on March 16, 2015 at 8:02am

Do you happen to have any video examples from the air?


Moderator
Comment by Roberto Navoni on March 16, 2015 at 11:33am

Melih, you are doing a great job ... are you using pic for your digital to pal convertion  ?  I see  a lot of project that use Super Osd or other pal video generator on PIC. 

Comment by Marc Dornan on March 16, 2015 at 11:36am

I was looking at a video from Virtual Robotix where they have a similar module based on the same FLIR Lepton breakout board where they indicate temperature readings are possible. Here it is: https://www.youtube.com/watch?v=MpA2jp3FnIk

Is this the same sensor? If so how have VR managed to get temperature readings? Or am I confused? 

Comment by Sashi Ono on March 16, 2015 at 11:41am

Nice work. I'm glad someone added analog out the lepton. 

Anyone interested the lepton and breakout, There is a ton of info here

http://www.pureengineering.com/projects/lepton

Comment by Sashi Ono on March 16, 2015 at 11:43am

Melih, you also want to check out the shuttered version of the lepton here:

https://www.tindie.com/products/PureEngineering/flir-lepton-thermal...

This will solve calibration issues that come with the regular lepton. 

Comment by Sashi Ono on March 16, 2015 at 11:46am

Also, Melih, I'm not sure what deal Flir is getting you, but you might want to jump on this groupgets buy here. 

https://groupgets.com/campaigns/66-flir-lepton-thermal-imager-round-6

You might want to think about selling your board there as well. (just an idea)

Comment by Marc Dornan on March 16, 2015 at 12:08pm

Sashi - looks like you answered my question. I suppose it needs to be shuttered.

Comment by Sashi Ono on March 16, 2015 at 12:15pm

The ones in the photo are non shuttered.  There is a shuttered version that will fit in the same socket though, and shouldn't require any firmware changes. 

Comment by Melih Karakelle on March 16, 2015 at 12:58pm

@Nick,  I hope I will take a video tonight from my balcony. I'm waiting some parts for real aerial video.

@Roberto, sorry I cannot talk about circuit design details, this is not an open-source project. May be later. 

@Sashi & Mark,
I cannot share the original FLIR documentations about telemetry because of NDA.
But, I can say it's nearly impossible with or without shutter. Shutter is not important, you can do that with any flat surface because of very small lens diameter. Flat surface calibration is really simple process and we have a button for modes and calibration on the camera.
The problem is not shutter, the problem is other factors (~10 different factor) 
The radiation coming from:

  • Camera internal structure 
  • Lens
  • Air 
  • Surface (the object)
  • Other objects(reflection)

But we want to know only surface temperature.
Air temperature,thickness (distance from the surface) and pressure is important factors. Surface reflection rate is really important. For example, Some materials are transparent, some of them working like a mirror in FIR band.

FLIR sharing large mathematical equations to calculate the right temperature. It's simply impossible without computer processors.(VR's video from raspberry PI)  and also FLIR is suggesting 2 different black body(lab equipment) and external temperature sensor for shutter for calibration. After all, all calculations will be rubbish if your propeller changes the camera temperature :)

DroneThermal can show the max-min-spot raw sensor values on the screen. So, you can use these values as reference. But we cannot give you right surface temperature.

FLIR announced some details about radiometric Lepton modules. They will make error correction for camera body and lens radiation but the air and reflections still there.


Moderator
Comment by Roberto Navoni on March 16, 2015 at 1:11pm

@Marc 

yes in our design we evaluate the temperature for each pixel. As told by Nick we are under NDA with Flir ,too about the algorithm for estimate the temperature . 

@Nick 

we don't use RaspberryPI in our demo but VR uBrain 5.2 it's based on STM32F4 processor with on board nuttx  operating systems in our design actually we are using about 50 % of cpu performance , for storing , streaming and evaluate temperature sensor for each point. For this kind of feature we need read data from spi and telemetry from i2c bus.

We are evaluating to implement Video Pal on STM32 for have analog input , too but isn't a priority.

best

Roberto 

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